During the spring of 1899, American military planners sought to end the war by sending two military forces out to destroy the marauding army of Philippine leader Aguinaldo, hiding in the hinterlands north of Manila. Major General Henry W. Lawton commanded one unit. His troops advanced through rugged terrain, intense heat, and drenching rainstorms, and came upon the fortified town of San Miguel de Mayumo.

Birkhimer led an advance scout force of eighteen soldiers, trailed by two companies of troops, to study San Miguel de Mayumo’s defenses. The advance scouts ran into 300 Filipino troops in an open field near the Rio Grande River. Birkhimer’s badly outnumbered scouts charged 150 yards across an open field to engage the Filipino flank. The surprised Filipinos withdrew across the river behind them, with Birkhimer and his scouts in pursuit. They took a bridge, charged into San Miguel and held it for several hours until support companies arrived.